Chapter 1:Exploring the Network Introduction to Networks
Chapter 1: Objectives After completing this chapter, students will be able to: Explain how multiple networks are used in everyday life. Explain the topologies and devices used in a small- to medium-sized business network. Explainthe basic characteristics of a network that supports communication in a small- to medium-sized business. Explain trends in networking that will affect the use of networks in small to medium-sized businesses.
Chapter 1 • 1.1 Globally Connected • 1.2 LANs, WANs, and the Internet • 1.3 The Network as a Platform • 1.4 The Changing Network Environment • 1.5 Summary
Interconnecting Our LivesNetworking Impacts in Our Daily Lives • Networks support the way we learn. • Networks support the way we communicate. • Networks support the way we work. • Networks support the way we play.
LANs, WANs, and InternetsComponents of a Network There are three categories of network components: • Devices • Media • Services
Components of a NetworkEnd Devices Some examples of end devices are: • Computers (work stations, laptops, file servers, web servers) • Network printers • VoIP phones • TelePresence endpoint • Security cameras • Mobile handheld devices (such as smart phones, tablets, PDAs, and wireless debit / credit card readers and barcode scanners)
Components of a NetworkNetwork Infrastructure Devices Examples of intermediary network devices are: • Network Access Devices (switches, and wireless access points) • Internetworking Devices (routers) • Security Devices (firewalls)
LANs and WANsTypes of Networks The two most common types of network infrastructures are: • Local Area Network (LAN) • Wide Area Network (WAN). Other types of networks include: • Metropolitan Area Network (MAN) • Wireless LAN (WLAN) • Storage Area Network (SAN)
Reliable NetworkSupporting Network Architecture As networks evolve, we are discovering that there are four basic characteristics that the underlying architectures need to address in order to meet user expectations: • Fault Tolerance • Scalability • Quality of Service (QoS) • Security
Reliable NetworkProviding QoS Examples of priority decisions for an organization might include: • Time-sensitive communication - increase priority for services like telephony or video distribution. • Non time-sensitive communication - decrease priority for web page retrieval or email. • High importance to organization - increase priority for production control or business transaction data. • Undesirable communication - decrease priority or block unwanted activity, like peer-to-peer file sharing or live entertainment.
Network TrendsNew trends Some of the top trends include: • Bring Your Own Device (BYOD) • Online collaboration • Video • Cloud computing
Network TrendsBring Your Own Device (BYOD) The concept of any device, to any content, in anyway is a major global trend that requires significant changes to the way devices are used. This trend is known as Bring Your Own Device (BYOD).
Network TrendsCloud Computing Cloud computing offers the following potential benefits: • Organizational flexibility • Agility and rapid deployment • Reduced cost of infrastructure • Refocus of IT resources • Creation of new business models
Network TrendsData Centers A data center is a facility used to house computer systems and associated components including: • Redundant data communications connections • High-speed virtual servers (sometimes referred to as server farms or server clusters) • Redundant storage systems (typically uses SAN technology) • Redundant or backup power supplies • Environmental controls (e.g., air conditioning, fire suppression) • Security devices
Network SecuritySecurity Threats The most common external threats to networks include: • Viruses, worms, and Trojan horses • Spyware and adware • Zero-day attacks, also called zero-hour attacks • Hacker attacks • Denial of service (DoS) attacks • Data interception and theft • Identity theft
Network SecuritySecurity Solutions Network security components often include: • Antivirus and antispyware • Firewall filtering • Dedicated firewall systems • Access control lists (ACL) • Intrusion prevention systems (IPS) • Virtual Private Networks (VPNs)
Exploring the NetworkingSummary In this chapter, you learned: • Networks and the Internet have changed the way we communicate, learn, work, and even play. • Networks come in all sizes. They can range from simple networks consisting of two computers, to networks connecting millions of devices. • The Internet is the largest network in existence. In fact, the term Internet means a ‘network of networks. The Internet provides the services that enable us to connect and communicate with our families, friends, work, and interests. • The network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which communication can occur. It is made up of network components including end devices, intermediate devices, and network media.
Exploring the NetworkingSummary (cont.) In this chapter, you learned: • Networks must be reliable. • Network security is an integral part of computer networking, regardless of whether the network is limited to a home environment with a single connection to the Internet, or as large as a corporation with thousands of users. • The network infrastructure can vary greatly in terms of size, number of users, and number and types of services that are supported on it. The network infrastructure must grow and adjust to support the way the network is used. The routing and switching platform is the foundation of any network infrastructure.